This chapter explores the adage that "possession is nine-tenths of the law." At face value, the adage would have it that the law of property follows from the facts on the ground - implicitly, the results of superior power, as in a game of Hawk/Dove or Chicken, where one party defers and the other takes the prize. Courts have distanced themselves from this view, however, and for good reason. It is only in times and places where the law has little force or none at all that possession flows simply from superior force. On closer examination of the legal meaning of possession - especially in two areas where possession supposedly matters, first possession and adverse possession - it emerges that for legal purposes, "possession" generally means acting the way an owner would. Thus for legal purposes, legality, or at least the appearance of legality, determines the meaning of possession, rather than the other way around.